In 1967 Harley Copp, Walter Hayes and Henry Taylor reached an agreement with Cosworth to develop an engine for Ford of England. The objective was to develop and engine with better performance than the twin-cam Lotus-Ford. Keith Duckworth was engaged full-time on the DFV engine so Mike Hall took on the design responsibilities. The new engine was based on the Ford Kent block and would use the same basic cylinder head breathing as the earlier FVA 4-cylinder and the V8 DFV.
In late 1964, the FIA issued the regulations that would govern Formula 1 starting in 1966. The new rules allowed a maximum engine capacity of 3.0 liters or 1.5 liters supercharged. Also in 1964 Leonard Lee announced that Coventry Climax would not continue as an engine provider after 1965. With Coventry Climax’s withdrawal from the sport the British teams, excluding BRM, would require a new engine supplier. Cooper entered an alliance with Maserati for use of its V12 engine. Brabham went for simplicity with Repco of Australia developing SOHC cylinder heads for the aluminum Oldsmobile F85 V8 cylinder block. Lotus signed a short-term deal with BRM to use its new H16 engine. The BRM engine would not be ready until late in the season so Lotus owner Colin Chapman convinced Leonard Lee to provide a 2.o liter upgrade to the Coventry Climax engine for Lotus to use in 1966.
